“Augmented reality” is an environment that includes both virtual and real-world elements. For example, a projector may display (or “overlay”) an image on real-world objects. To get the projected image to correctly overlay the real-world environment, the image may be scaled and warped to match the real-world objects or surfaces upon which it is projected. This scaling and warping compensates for the projector's projection angle, distance to the real-world objects, and three-dimensional curves on the projection surface in the real-world.
Scaling and warping algorithms are known. If one can correlate a sufficient number of points in the underlying image to be projected with locations on the projection surface, the underlying image can be scaled and warped to match the projection surface using known methods. Correlating points within the underlying image with locations on the projection surface can be a hard problem, especially if the projector is in motion.